It is often advantageous to include sensory agents such as aroma and flavour in many soluble beverage products. For example, it generally found in the coffee industry that consumers associate quality coffee with a good coffee aroma. If a coffee product lacks coffee aroma, consumer perception of the product is adversely affected. Unfortunately, soluble (or as it is commonly known, instant) coffee is almost entirely aromaless. For this reason, it is conventional to trap coffee aromas which are given off during the processing of the soluble coffee and to later reincorporate these aromas into the soluble coffee.
Various techniques have been attempted for reincorporating coffee aroma into soluble coffee. One commonly used technique for reincorporating the aroma is to first capture the aroma into a suitable substrate. Suitable procedures for carrying out the capture of the aroma are disclosed in, for example, U.S. Pat. Nos. 3,823,241, 5,030,473, and 5,222,364 but many other techniques are known. Usually a coffee oil, an emulsion of coffee oil, or a coffee extract, is used as the substrate. The aroma-containing substrate is then usually mixed with the soluble coffee powder prior to the coffee powder being filled into containers, which are then sealed. Unfortunately, the aroma usually escapes readily from the substrate, requiring the coffee jar to be carefully sealed to retain the aroma. However, once the consumer breaks the seal, it is usually not too long before the aroma is lost. Also, although these techniques are able to provide aroma in the coffee jar for a limited time, very little aroma is provided above a cup of coffee made from the coffee powder.
These problems have led to various attempts to encapsulate the coffee aroma to retain the aroma until the soluble coffee is dissolved in hot water. The intention is to cause the release of coffee aroma from the cup. One attempt is described in U.S. Pat. No. 3,989,852 which discloses a process of preparing coffee aroma capsules by formulating the aroma into a viscous medium with a low moisture content. The viscous medium is then formed into tacky particles which are then rolled in a film forming agent. The film forming agent is then allowed to dry to provide a capsule about the aroma. Unfortunately, the amount of aroma that may be encapsulated per capsule using this process is rather low. It is also found that the capsules do not retain the aroma for any considerable length of time.
European patent application 0008015 discloses a process for encapsulating coffee aroma in which an aromatic coffee distillate is mixed with coffee oil to provide a water-in-oil emulsion. The water-in-oil emulsion is then atomized and the individual droplets are rolled in fine coffee powder. The droplets are then allowed to dry to form a capsule of dried coffee solids about an oil core which contains the aroma. Although the capsules are satisfactory, some aroma loss occurs during the encapsulation process.
Canadian Patent 837021 discloses a process for encapsulating coffee aroma in which coffee oil is homogenized with a coffee extract containing up to 40% coffee solids. An aroma condensate is then stirred into the homogenized mixture. The mixture is then sprayed onto soluble coffee powder and the coffee powder mixed and tempered to equilibrate the moisture throughout the coffee powder. After tempering, the moistened powder is vacuum dried. Unfortunately, considerable amounts of aroma are lost during vacuum drying.
Similar problems occur with the encapsulation of flavours and aromas in beverages such as soluble teas, cocoa and chocolate drinks, instant dried soups, flavoured coffees (roast and ground as well as soluble), coffee and tea creamers, and the like.
Therefore there is still a need for a simple, yet effective encapsulation technique which provides capsules having good capacity for sensory agents and good retention of the encapsulated sensory agent.